The general purpose and intent of this project is to conduct test, research, and experiments directed toward the use, improvement, and development of clinical procedures and instruments for measuring functions or properties relating to vision and the eyes. This has consisted primarily of subjective measurements of visibility and chromaticity thresholds. Electroretinography, which is an objective measurement of electrophysiological activity in the retina, is used only in selected cases because of its limited usefulness. The most significant work of the year was the measurment and analysis of defects in color vision with the chromagraph. This is our new instrument which permits the measurement of any type of color defect, many of which are too subtle or too bizarre to be shown with the conventional tests.